Coaxial relay



Feb 5, 1952 c. F. MILLER x-:TAL 2,584,901

COAXIAL RELAY Filed Sept. 17, 1947 3 Sheets-5119? 1 TIE- 1. 5

O CHA/Rl 6 JFFFEPS O/V MUR/JA y C99 5a 4./5

Feb. 5, 1952 C. F. MILLER ETAL COAXIAL RELAY Filed Sept. 17, 1947 3 Sheets-Sheet 2 :FI Er- 45a I 5 TCT- E IN V EN TORS A TTORN Y Feb. 5, 1952 Filed sept. 17. 1947 TRANS/*H7759 HiFi/VFR C. F. MILLER ETAL COAXIAL RELAY 3 Sheets-Sheet 3 Patented Feb. 5, 1952 Murphy, Baltimore, Md., assignors to- VPrice Electric Corporation, Frederick, Md., a corporation of Maryland Application September 17, 1947, Serial No. 774,590

2 Claims. (Cl. 200-104) This invention relates ibroadly'to high frequency electrical switching systems and more particularly to a high frequency electrical switch for coaxial cable systems.

One of the objects ofthe invention is to provide an improved construction of remotely con-V trolled electrical switching apparatus having lowelectrical capacity and minimum tendency for sustaining standing waves in the coaxial transmission line.

`Another object of the invention is to provide a practical construction of remotely controlled relay for coaxial transmission lines for switching the transmission line to transmission and receiving conditions while maintaining a high electrical eiflcency of the transmission line.

Another object of the invention is to provide a construction of remotely controlled relay for transferring a transmission line from transmitting to receiving positions while maintaining va match in the impedances of the! several lines which are thus interconnected.

Still another object of the invention is to provide a construction of remote controlled coaxial relay for transmission lines which does not cause reflection of energy being transmitted through the relay.

Other and further objects of the invention reside in the mounting means and actuating means for the coaxial relay as set forth more fully in the specification hereinafter following by reference to the accompanying drawings in which:

Figure 1 is a front elevational View of the coaxial relay; Fig. 2 is a side elevational View of the coaxial relay shown in Fig.' 1; Fig. 3 is a top plan view of the coaxial relay; Fig. 4 is a longitudinal vertical sectional View through the relay taken substantially on line 4-4 of Fig. 2; Fig. 5 isa vertical sectional view through theV relay taken -substantially on line 5 5 of Fig. 4 with certain of the parts shown in elevation; Fig. 6 is a transverse sectional view taken substantially on line 6-6 of Fig. 4; Fig. 7 is a transverse sectional view through the relay operating armature and the spring pile-up contact assembly taken substantially on line 'l-l of Fig. 4; Fig. 8 is a perspective view of the magnetic frame of the control relay for the coaxial switching apparatus; Fig. 9 is a perspective View of the spring pile-up support which is carried by the magnetic frame of the control relay; Fig. 10 is a perspective View of the operating armature of the control relay; Fig. 11 ls a perspective view of the plate which is carried by the armature of Fig. 10; Fig. l2 is a perspective rview. of `the resilient spring member which is secured to the assembled plate'of Fig. 1l andarmature of Fig. 10 for imparting movement to the coaxial transfer switch; Fig. 13 is afperspective view of the insulation member which transmits movement from the armature of Fig. lO to the spring pile-up assembly; Fig. 14 shows a typical installation of the coaxial relay in transferr-ing connections between an antenna system and a transmission and receiving system; Fig. ll5 shows the application of our coaxial relay to an installation where a selected antenna of two antennae is switched to a receiver or transmitter; and Fig. 16 illustrates another typical installation of the coaxial relay in switching one antenna sysf throughl the relay. The construction of the relay is such that the relay may be located at any desired remote location in the line and electrically controlled yfor transferring `connectionsyfor example, betweenhan antenna system and a trans-lr mission and receiving system. InV a typical in-A stallation employing, for example, 750`watts of' radio frequency power, the relay may be designed for use with 52 o hm cable and cable fittings which terminate in the relay housing. The antenna or radiating system connected to the load end of the coaxial transmission line must present a real (resistive) impedance of 52 ohms to the antenna end of the transmission cable. This is diirlcultto accomplish, especially with beam antennasystems,l and failure at this point is the Amost common source of trouble in transmission systems. It

must be remembered that an antenna system' which has a calculated impedance of 52 ohms at the driving Aterminals when considered alonemay present a linefterminating impedance whichl diff-y fersyconsiderably from 52 ohms when connected to the coaxial line, as a result of the current which ows on theuouter conductor ofthe 'line due to capacitive coupling with the antenna proper. It must be remembered also that the addition of reflectors and directors ,to a beam antenna system will change ythe impedance which the radiatingsystem presents to the transmissionN line.

Other abnormal circumstances and conditions may result in standing waves of some magnitude. When standing waves exist in the antenna to transmitter line not only the antenna transfer relay but the entire antenna system must be derated. This reduction in rating results from the fact that excessive voltages and currents exist at regular intervals in the line, also the overall power loss is greater. The amount of reduction in relay capacity will depend upon the seriousness of the standing waves in the line.

Referring to the drawings in detail reference characters I and 2 designate supporting brackets arranged to mount the coaxial relay` adjacent a support 3. The switch of the coaxial relay is housed within a pair of coacting cavity members 4 and 5 formed from non-magnetic material and adapted to be bound together at their opposite ends by fastening screws E passing through plate 1 beneath bracket 2 and extending in the ends of coacting cavity members 4 and 5 at one end of the housing while at the other end of the housing screws 8 pass through apertures formed in the corners of bracket I which is centrally apertured for the passage of the cylindrical end of the transmission cable tting ID and through flange 9 of the transmission cable fitting I0. Lock washers 8a are disposed beneath the heads of each of the screws 8. Thus the bracket I which is centrally apertured for the passage of the cylindrical portion Illa of the transmission line cable tting I serves to center the coaxial relay housing in position with respect to the cavitsr members 4 and 5 and form a supporting means for the end of the housing.

The cavity members 4 and 5 are internally recessed at the upper end of the housing, as represented by semi-cylindrical recesses 4a and 5a to provide by their coaction a cylindrical recess for receiving the pair of semi-cylindrical coacting block members Il and I2. The semi-cylindrical coacting block members Il and I2 are diametrically divided and serve as supports for the upper end of switch arm I4 and form spacing means for spacing the switch arm I4 with respect to the inner walls 4b and 5b of the cavity members 4 and-5. The blocks I I and I2 secure and definitely locate the switch arm I4 in positionin the cavity between members 4 .and 5 without` the use of screws or other fastening means. The use .of rivets, screws or other methods of securing switch arm I4 in accurate position between cavity members 4 and 5 would in general increase the capacity (capacitance) to ground and decrease the voltage break-down strength of the unit. The switch arm I4 is secured to the post I5 which is supported in the sleeve of insulation material represented at I6 in the transmission cable tting I0. The post I terminates in socket sleeve I5a into which the end of the coaxial cable may be detachably connected.

The switch arm I4 extends longitudinally through the cavity members 4 and 5 intermediate the walls 4b and 5b thereof and terminates in a pairk of contacts I1 and I8 on opposite sides of the switch arm I4. The lower ends of the cavity members 4 and 5 are provided with transversely extending cylindrical apertures 4c and 5c axially aligned with each other for receiving the transmission cable ttings shown at I9 and 20. The transmission cable ttings I9 and 20 are similar to the ttings I0 and each constitute an externally screw-threaded sleeve and each containing an insert of insulation material as represented at.

The insert 2| forms a support for a tionary contact 24 terminates resilient sleeve 24a adapted toreceive the terminal of a coaxial cable.

The electromagnetic operating mechanism which is remotely controlled for displacing switch arm I4r fromthe normally biased position shown in Fig. 4in which connection is established between contact II and contact 23 to the position in which connection is established between contact l8 and contact 24, is mounted externally of the housing constituted by cavity members 4 and 5. The electromagnetic operating mechanism includes a laminated magnetic frame structure shown more clearly in Fig. 8 consisting of laminated substantially U-shaped magnetic members represented at 25. The magnetic substantially U-shaped members are slotted adjacent one end as represented at 25a forming a pole piece, the area of which is substantially enlarged by magnetic plate 26 secured to the magnetic-laminations 25 and extending to the slot 25a therein at one end and projecting substantially beyond the laminations 25 at the opposite end. The magnetic laminations 25 are apertured at the end opposite the magnetic plate 26 as representedv at 25D and screw-threaded to form a securing means for securing screw 21 which passes through the bracket member 28 for thus securing the bracket member 28 in position with respect to the magnetic laminations 25. The bracket member 28 is shown more clearly inrFig. 9.

Bracket member 28Y is provided vwith a pair of v right angularly extending tongues 28a at one end and a centrally angularly projecting lug 28h be-` tween the tongues 28a. Tongues 28a are secured by means of screws 29 to the side of cavity mem.- .Y

ber 4 thereby locating magnetic members 25 :with respect to the housing formed by cavity members 4 and 5. The lug 28h serves as a securing means for one end of the coil spring 3|), the other` end of which is engaged through the projecting end (lla of magnetic armature member 3|. The end3la of armature memberr 3l is sufficiently reduced in section to readily extend through aperture 28er in bracket member 28 so that magnetic armature 3I is free to rock angularly about the prof jecting ends 25e of the magnetic vlaminations 425 when armature 3l is lattracted by the pole piece adjacent magnetic plate 26 of the magnetic laminations 25. Coil spring 30 tensions armature for limited movement withl respect tomagnetic plate 26. shown more particularly in Fig. 1l secured thereto by suitable rivet members 33. Plate member 32 has the end 32a thereof bent in a plane sub- The end 32a is slotted as represented at 32band is pro- Y stantially normal tothe. plane of plate 32,

vided with an apertured extension 32e thereon. The slot 32h in the end 32a of plate 32fserves to permit the passage of the end ofl the resilient. plate 34 shown more particularly in Fig. l2, The resilient plate 34 has a bifurcated en d portionr shown at 34a which extends through the slot 32h: and engages Vthe vannular neck A35a of reduced section of plunger -member.,35. vPlunger..member-3lI Armature 3l hasplate member 32 Y extends slidably through the vtubular member 36 which is screw-threaded into the side of cavity member 4. Tubular membel1` 36 is disposed intermediate theY contact portion I`I-I8 of switch arm I4 and the xed end of the switch arm I4 and intermediate the magnetic frame ofthe magnetic operating mechanism and the transmission cable fitting I9. .A

The plunger member which slidably operates in tubular member 36 is recessed in the end thereof as represented at 35h andreceives the actuating member 31 formed from insulation material. kActuating member 31 of insulation material engages switch arm I4 and by reciprocal movement thereof serves to shift switch arm I4 from the biased position illustrated in Fig. 4 'with contact I'I in engagement with contactl 23 to the opposite position with contact I8 in engagement with contact 24.

lPlunger 3.5 is controlled` as explained by the electromagnetic operating mechanism and is definitely limited in-its reciprocative movement by the mounting ofthe armature 3 I. Bracket 28 isL shaped as represented more clearly in Fig. 9 to provide for a flattened supporting area 28d and an angularly extending tongue 28e. The tongue 28e serves as a limiting stop for the movable armature system, abutment being established between plate 34 andtongue 23e in the deenergized position of armature 3 I The apertured end 32e of plate 32 serves as a securing means for the plate 38 of insulation material. Plate 38 includes a pail1 of oppositely disposed slots 38a and 38D which engage the projecting ends of contact springs 39 and 40. The contact springs 39 and 40 are partvof the spring pile-up assembly represented generally at 4I which is supported by the iiattened area 28d of bracket 2B. The spring pile-up assembly may comprise any complement, of contacts which may be required. For purposes of illustration I have shown contact springs 39 and 40 as carrying contacts 39a and 40a as represented more clearly in Fig. 7. Contacts 39a and 40a are arranged to coact with iixed contacts 42a and 43a carried by spring contact strips 42 and 43 respectively and so arranged that one set of contacts 40a and 43a are closed while the other set of contacts 39a and 42a are open. The several spring contact strips are substantially insulated from each other and maintained in operating position by the insulation strips 44 and securing screws 45.

The magnetic frame 25 which directly abuts against the side of the housing formed by cavity member 4 is wrapped with insulation material 46 which encircles the housing constituted by cavity members 4 and 5. Around this insulating wrapping 46 I arrange the operating winding of the relay system as shown at 4'I. The operating winding 4`I is provided with terminal members 48 and 49 for connection of the opposite ends of the winding to the remote control circuit.

The assembly of the relay i's accomplished by first introducing the frame 25 around one side of the insulated core 46 with the actuating winding 4'I mounted thereon and then sliding the upper end of the housing through the insulated core 46 and thereafter proceeding to anchor the bracket 28 in position with respect to the housing by screws 29 and proceeding to effect the assembly of the armature 3I and the spring pile-up assembly 4I. The plunger 35 is mounted in position and the bifurcated end 34a of spring member 34 secured around annular recess 35a whereupon the relay is ready for connection of the co- 6. axial ycables with the transmission cable fitting.

-It willbe observed that each of the transmission cable ttings I0, I9 and 20 are externally screw-threaded and are provided with serrated teeth adapted to establish a fluid tight connection with the gasket in the end of the coaxial cable transmission line which is connected to the fitting. v v f With reference to Fig. 14 we have illustrated a. combination block and schematic diagram showing a typical application of the coaxial relay designated at 50 as applied to a radio communication system. The coaxial relay 50 is shown in the unenergized position, as is the power control relay 5I. Power control relay 5I includes actuating winding 52 and set of contacts 53. Under the conditions illustrated the transmitreceive switch 54 is open. The normally closed auxiliary contacts 4I of the coaxial relay 5D energize the receiver 55 while the coaxial contacts through switch arm I4 of the coaxial relay 5I) connect the antenna system 56 to the receiver input cable 5'I.

When the transmit-receive switch 54 is closed, one side of this (double-pole, doublethrow) switch closes the coil circuit 4'I to the coaxial relay 50. The other side of this switch 54 closes the coil circuit 52 to the power control relay 5I (as soon as the coaxial relay 50 operates to close its normal open auxiliary contacts 4l). It can be seen that with this circuit arrangement, the power control relay 5I cannot. operate until the coaxial relay 50 has connected the antenna system 54 to the transmitter output cable 56, leading to transmitter 59.

As soon as the power control relay 5I operates set of contacts 53 its normally open auxiliary contacts 5353 lock this relay in electrically. Contacts 53"-53 53-53' energize the transmitter 59 by closing the primaries of the high voltage plate supply transformers. When the transmit-receive switch 54 is open (i. e. thrown to the receive position) the lock-in contacts 53'-53' of the power control relay 5I hold the coaxial relay 5i! in the operated position until the power control relay 5I has fallen open and de-energized the transmitter 59 and its output cable 58. This circuit is required in order to prevent the operation of the coaxial antenna contacts while the transmitter is energized and delivering power to the antenna.

Fig. 15 shows the application of the coaxial contacts of the coaxial relay 50 to a situation where it is desired to transfer the antenna cable 6l] of a given receiver (or transmitter) 6I from one antenna system 62 to another antenna system 63. This problem arises, for example, where two antenna systems having diierent directional characteristics are to be employed with a single receiver or transmitter.

Fig. 16 shows an application of the coaxial relay to the problem of switching one antenna system 64 between two receivers or two transmitters, [i5-66, connected through cables fil- 68 with the coaxial relay 50. This problem arises in many installations where a standby receiver or transmitter is held in readiness for operation in the event of failure of the operating equipment.

The relays of Figs. 15 and 16 do not show the 'auxiliary contacts because these contacts may, or may not, be required.

While we have illustrated certain applications of the coaxial relay of our invention, we realize that many other applications of our invention will. suggest themselves and Vthat variation instructural detail of thecoaxial relay may be made. we desire that it be understood that no limitations upon our invention are intended, other than may be imposed bythe scope ofthe appendedv claims.

What We claim as new and desire to secureby Letters Patent of the United States is as follows:

l. A high frequency electrical switch comprising a pair of linearly extending coactingzcavity membersl terminating in flat coplanar ,surfaces at'each end thereof, said cavity members hav-ing semi-cylindrical internally alignedv recesses at their upper ends, a sleeve of insulation material mounted in said internally aligned recesses and supporting an angular-ly displaceable switch armextending centrally between said coacting cavity members, said cavity members being recessed at oppositesides thereof adjacent their lower'ends, stationary contact members insulatingly mountedv in each of the last mentioned recesses and directed vtoward each other on opposite .sidesofsaid angularly displaceable switch arm, contacts carried by said switch arm operative to establish make and breal: connect-ion with said stationary contacts, a substantially U-shaped electromagnetic frame structure having a portionthereof mounted incontacting relation against one oi` the external sidesof one of said cavity members, anelectromagnetic winding surrounding thatportion of the Vsubstantially U-shaped electromagnetic frame structure which is disposed` in contacting relation with the externalside ofgaid one of said cavity members .and surrounding they cavity members, an armature movable with respect to said frame structure and controlledrby said-electromagnetic winding and adisplaceable member operated by said armature and through one wall of one of saidcavity members for moving said switch arm from one of said stationary contacts to the other.

2. lAhigh frequency electrical switch as set forth in claiml Y1. .in which the ,cavity-.member through which said displaceable member operates supports a tube at one side thereof through which said displaceable member slides and wherein said, displaceable member has a lost motion connecfA tion atits exterior end with said armature and carries a terminus of insulation `material at the other end establishing tangential contact with one side of said switch arm.

CHARLES FRANK MILLER; CHARLES J. MURPHY.

REFERENCES CITED The following references-.are of record inthe le of this patent:

UNITED STATES PATENTS OTHER REFERENCES Electronics," January 1941, page '79.y 

